Ethernet lib: add AdvancedChatServer example

Author: leonardocavagnis

libraries/Ethernet/examples/AdvancedChatServer/AdvancedChatServer.ino

@@ -0,0 +1,126 @@
+/*
+ Advanced Chat Server
+
+ A more advanced server that distributes any incoming messages
+ to all connected clients but the client the message comes from.
+ To use, telnet to your device's IP address and type.
+
+  Usage:
+  1. Upload this sketch to your board.
+  2. Make sure your board is connected to the network and note its IP address.
+  3. From a computer on the same network, open a terminal and connect via Telnet:
+
+  - On macOS or Linux (using netcat if telnet is not available):
+      telnet <board_ip> 23
+      # or, if telnet is missing:
+      nc <board_ip> 23
+
+  - On Windows (Command Prompt):
+      telnet <board_ip> 23
+      # If 'telnet' is not recognized, enable it in "Windows Features".
+
+  4. Type a message and press Enter.
+  Your message will be broadcast to all connected clients except you.
+
+  Example:
+  telnet 192.168.1.177 23
+
+  Press CTRL + ] then 'quit' to exit Telnet.
+
+ */
+
+#include "ZephyrServer.h"
+#include "ZephyrClient.h"
+#include "ZephyrEthernet.h"
+
+// The IP address will be dependent on your local network.
+// gateway and subnet are optional:
+IPAddress ip(192, 168, 1, 177);
+IPAddress myDns(192, 168, 1, 1);
+IPAddress gateway(192, 168, 1, 1);
+IPAddress subnet(255, 255, 255, 0);
+
+
+// telnet defaults to port 23
+ZephyrServer server(23);
+
+ZephyrClient clients[8];
+
+void setup() {
+  // start serial port:
+  Serial.begin(9600);
+  while (!Serial) {
+    ; // wait for serial port to connect. Needed for native USB port only
+  }
+
+  // in Zephyr system check if Ethernet is ready before proceeding to initialize
+  Serial.print("Waiting for link on");
+  while (Ethernet.linkStatus() != LinkON) {
+      Serial.print(".");
+      delay(100);
+  }
+  Serial.println();
+
+  // initialize the Ethernet device
+  Ethernet.begin(ip, myDns, gateway, subnet);
+
+  // Check for Ethernet hardware present
+  if (Ethernet.hardwareStatus() == EthernetNoHardware) {
+    Serial.println("Ethernet shield was not found.  Sorry, can't run without hardware. :(");
+    while (true) {
+      delay(1); // do nothing, no point running without Ethernet hardware
+    }
+  }
+  if (Ethernet.linkStatus() == LinkOFF) {
+    Serial.println("Ethernet cable is not connected.");
+  }
+
+  // start listening for clients
+  server.begin();
+
+  Serial.print("Chat server address:");
+  Serial.println(Ethernet.localIP());
+}
+
+void loop() {
+  // check for any new client connecting, and say hello (before any incoming data)
+  ZephyrClient newClient = server.accept();
+  if (newClient) {
+    for (byte i=0; i < 8; i++) {
+      if (!clients[i]) {
+        Serial.print("We have a new client #");
+        Serial.println(i);
+        newClient.print("Hello, client number: ");
+        newClient.println(i);
+        // Once we "accept", the client is no longer tracked by EthernetServer
+        // so we must store it into our list of clients
+        clients[i] = newClient;
+        break;
+      }
+    }
+  }
+
+  // check for incoming data from all clients
+  for (byte i=0; i < 8; i++) {
+    if (clients[i] && clients[i].available() > 0) {
+      // read bytes from a client
+      byte buffer[80];
+      int count = clients[i].read(buffer, 80);
+      // write the bytes to all other connected clients
+      for (byte j=0; j < 8; j++) {
+        if (j != i && clients[j].connected()) {
+          clients[j].write(buffer, count);
+        }
+      }
+    }
+  }
+
+  // stop any clients which disconnect
+  for (byte i=0; i < 8; i++) {
+    if (clients[i] && !clients[i].connected()) {
+      Serial.print("disconnect client #");
+      Serial.println(i);
+      clients[i].stop();
+    }
+  }
+}